Misbehaving “212” rapper Azealia Banks was once arrested for slicing her sister with a box cutter in the “neck, the arm and the hand,” prosecutors disclosed on the eve of her bouncer boob-biting trial in Manhattan Criminal Court.

The incident in April 2009 is a past crime for the controversial performer that prosecutors hope to use against her if necessary for impeachment when she takes the witness stand as early as next week.

“This is a case where she slashed her sister in the neck, the arm and the hand with a box cutter,” Assistant DA Shea Donato said.

Banks pleaded guilty to attempted assault, but got special treatment because of her age at the time.